The present invention relates to an aerial photographing system with a camera for photogrammetry installed on a small type flying vehicle.
In recent years, with the progress of UAV (Unmanned Air Vehicle), photogrammetry using UAV has been developed by installing a camera for photogrammetry on UAV.
Normally, a UAV makes flight by tilting its vehicle body in forwarding direction, while the tilting of the vehicle body of the UAV is very likely to be influenced by its speed of propulsion and by wind, and a stability of the tilting is low. On the other hand, in aerial photogrammetry, it is necessary to photograph the images in vertical and downward direction with high precision, and the stability is required on the tilting of the camera.
Further, in aerial photogrammetry, it is necessary to have ground coordinates of the photographing point in order to perform ground orientation (absolute orientation) of an aerial photograph as taken. Conventionally, as a method of obtaining the ground coordinates of the UAV, a GPS device is installed on the UAV and the ground coordinates of the UAV are obtained by the GPS device.
However, since the GPS device obtains the ground coordinates by using radio waves from artificial satellite, ground coordinates of the UAV cannot be obtained by the GPS device in places where radio waves cannot be received, such as in a tunnel or urban areas and the like bristling with skyscrapers.